This invention relates to the configuration and structure of an aircraft, and, more particularly, to an aircraft having a removable payload module that forms the structural link between a forward fuselage segment and an aft fuselage segment.
An aircraft structure includes a fuselage, a wing, a tail, and one or more engines mounted to the aircraft. A payload such as passengers or cargo is typically carried within the interior of the fuselage. In some cases, the payload may be mounted at least in part exteriorly to the fuselage or affixed externally to the wing.
Some aircraft are optimized for a single type of purpose or mission, such as carrying only passengers, carrying only cargo, or various specific military missions. In other cases, the aircraft is made so as to be convertible between various purposes in order to maximize the potential utilization of the aircraft. In one example, a "cargo conversion" aircraft is built so that the interior of the fuselage may be arranged with rows of passenger seats for some applications. The rows of seats are removable so that containers of cargo may be placed into the interior of the fuselage for other applications. In another example, used with aircraft such as bombers having an internal bay, various packages may be placed into the internal bay. In yet another example, interchangeable external pods may be attached to the airframe.
While operable in specific types of applications, these approaches to convertibility have limitations. If the various payloads are so complex that extensive modifications to the aircraft structure are required in order to effect the conversion, the switching between payloads becomes prohibitively costly and time consuming. For example, some payloads may require access to the exterior of the aircraft, as for instrumentation ports, while other payloads may require that a portion of the payload reside exteriorly to the aircraft. These widely varying types of payloads require that the aircraft undergo extensive modifications, such as adding instrumentation ports or external support pylons to accomplish the conversion. To reduce the cost and time required to make the conversion, the instrumentation ports or external support pylons may be provided as permanent parts of the aircraft structure, but any addition of permanent structure that is used only part of the time reduces the flight efficiency of the aircraft. Such a reduction in efficiency may be acceptable in some situations, but it is not acceptable for aircraft which are expected to perform challenging missions such as long loiter times at high altitudes, for several different types of payloads.
There is a need for an improved aircraft configuration which is both highly flexible as to the types of specialized payloads that it can carry, and is also highly efficient in operation. The present invention fulfills this need, and further provides related advantages.